#include <bits/stdc++.h>

using namespace std;
int n, f[100005], ans;
vector <int> a[100005];
void dfs(int k)
{
    f[k] = 1;
    for(auto v : a[k])
        if(!f[v]) dfs(v);
}
int main()
{
    freopen("dfs.in", "r", stdin);
    freopen("dfs.out", "w", stdout);
    int m;
    scanf("%d%d", &n, &m);
    for(int i = 1; i <= m; ++i) {
        int x, y;
        scanf("%d%d", &x, &y);
        a[x].push_back(y);
        a[y].push_back(x);
    }
    for(int i = 1; i <= n; ++i) {
        if(!f[i]) ++ans, dfs(i);
    }
    printf("%d", ans);
    return 0;
}